Rheem Tankless Water Heater User Manual

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Additional Considerations
Do NOT install vent terminal under any patio or deck.
To help prevent moisture from freezing on walls and under 
eaves, do not locate vent terminal on the side of a building with
prevailing winter winds.
To help prevent water lines from freezing, do not locate vent
terminal on the side of a building with prevailing winter winds.
Do Not terminate vent directly on brick or masonry surfaces.  A rust
resistant sheet metal backing plate ( 1 x 1 foot)(30 x 30 cm) is
recommended behind vent.  (See Figure.)
Do NOT locate vent terminal too close to shrubbery, as flue gases
may damage them.
Caulk all cracks, seams and joints within six (6) feet (1.8 m) of vent
terminal.
Caulk around thimble face plate for weather tight seal.
All painted surfaces should be primed to lessen the chance of
physical damage. Painted surfaces will require maintenance.
Insulate vent pipe of water heaters exposed to cold conditions
(attics, crawl spaces, etc.) with inflammable material to help prevent
moisture from accumulating in vent pipe. The insulation should be
rated for the temperature and should not contain substances that
corrode the vent pipe.
Do NOT extend exposed vent pipe of indoor water heaters outside of
building.
Guard vent against accidental contact with people and pets.
Install outdoor water heater such that air inlet and flue outlet is
above anticipated snow level.
(1.8 m) 
If soffit vent is too close, 
block off and install new 
vent at another location 
Inside 
corner 
Caulk 
Caulk 
Caulk 
6' (1.8 m)  
caulk zone or 
to edge of 
window etc., starting 
within 6' (1.8 m) 
Rising moisture will collect under eaves 
4'
6' (1.8 m) caulk 
zone 
6' 
(1.2 m)
12” (30 cm)
WARNING
Moisture in the flue gas will condense as 
it leaves the vent terminal. In cold weather this condensate
can freeze on the exterior wall, under the eaves and on
surrounding objects. Some discoloration on the exterior of
the building is to be expected. However, improper location
or installation can result in severe damage to the structure
or exterior finish of the building.
Outdoor Water Heater
Indoor Water Heater
Inside
Corner
Caulk
6’ (1.8 m)
Caulk Zone
If soffit vent is too close,
block off and install new
vent at another location.
Caulk
Caulk
Rising moisture will
collect under eaves.
6’
4’
Wall thimble face plate 
(1.8 m)
6’ (1.8 m)
Caulk
zone or to edge of window
etc.,starting within 6’ (1.8 m).
RTV silicone caulk
(1.2 m)
13
12”(30 cm)